We owe to Rousseau the insight that if there were no nation-states there would be no wars, and to Hobbes the insight that without nation-states there would be no domestic order. Foreign policy choices often involve judgments about the lesser of these two evils. Over the next several years, the United States must decide whether its interests are better served by trying to preserve threatened nation-states or by dismantling them-not least in the case of Iraq.

Many welcome the decline of the nation-state, urging reliance on international institutions and networks-both public and private-to create a more peaceful world instead. Solutions to international challenges will come from the United Nations and the European Union first, and nations second. But as the nation-state declines, transnational terrorist networks rise; as nationalism recedes, tribalism and violent religious extremism take its place. Failed or dysfunctional states have become breeding grounds for civil wars, genocide and other atrocities, terrorism, famine and the spread of lethal diseases. Spillovers can profoundly impact the developed world.

Since September 11, failed or dysfunctional states have become the central challenge to American foreign policy and national security-a point rightly noted in these pages last year by former National Security Advisors Brent Scowcroft and Sandy Berger. [1] Had Afghanistan not been a failed state, its government might not have harbored Al-Qaeda. Had Iraq not been governed by a tyrannical clique of warlords, it might not have posed a threat to its neighbors and its own people.

The policy of the United States has been to maintain, by force if necessary, nation-states within their pre-existing, "internationally recognized" borders: either "nation-building" (Afghanistan) or "nation-reconstruction" (Iraq). But even before September 11, state failure was a critical national security concern. The United States slowly came to grips with the collapse of states such as Yugoslavia and sought to restore some semblance of functioning order in others such as Haiti, Rwanda and even Somalia. Throughout, the United States has shown a bias in favor of maintaining the status quo that may stretch back to the administration of the first President Bush, if not before.

We have not only sought to restore or impose a nation-state framework in troubled areas. We have also sought to transplant the democratic model of the nation-state that the United States embodies: a model of democracy that tempers majority rule with substantial protections for minorities and with guarantees of individual rights, private property and markets. While President Bush sounds almost millennial in praising the blessings of democracy and individual liberty, there are more practical reasons for the policy: Our government spreads democracy because it believes that democracy enhances American national security and stabilizes the international system, thus reducing the need for the United States to intervene abroad. For the Bush Administration, it has been the democratic nation-state or nothing.

While our current foreign policy leaders have not fully explained the mechanism by which democracy promotes international peace, the link may exist for three reasons. First, some studies indicate that democracies do not go to war with each other-so the more democracies there are in the world, the fewer threats there will be to the United States. Second, democracy is believed to encourage a market economy, which generates prosperity and therefore less desire for foreign conflict. Third, democracies are thought to discourage violence in favor of peaceable methods of debate, negotiation and compromise. Democracies, it is assumed, will refuse to heed the calls of extremist factions for wars against either the near (Shi‘a or Sunni) or far (Israeli or American) enemy. The United States's strategy of constructing democratic nation-states is thus designed to find an escape from the Hobbes-Rousseau conundrum and lead to a more stable, prosperous and peaceful world.

We agree that nation-states, because of their ability to police their borders and populations, remain the most reliable means of advancing international security in the end. Likewise, we think that the pro-democracy component of the overall U.S. strategy makes sense. But the United States and its NATO allies have made the mistake of believing that because the nation-state structure and democratic governance generally promote international security, every territory and people should be governed by a democratic nation-state. This belief is flawed because it assumes that, once given the opportunity to participate democratically as equal citizens in deciding questions of public policy, local populations will be induced to transcend identities of race, tribe or sect and to surmount a history of isolation and mistrust. But how can such trust be established before a viable democratic nation-state is in place?

In a region like the Middle East, where powerful group identities have been entrenched by centuries of conflict, the cost of being mistaken in trusting the good intentions of an historic enemy can be deadly. Hence we see outcomes like that so far in postwar Iraq: Until such time as a national government is strong enough to quell warring militias and police the streets, the promise of democracy will not overcome the historic antagonisms of the Shi‘a-Sunni rivalry; but no functioning, democratic national government can be securely established until the Shi‘a and Sunni communities have learned to trust each other.

As we see it, the Bush Administration's chief error in the realm of international law has been to insist on imposing the democratic nation-state structure on areas that can barely (if at all) govern themselves. The effort to remake the Middle East in the American image, though noble, has been misguided. The Bush Administration has mistakenly seen its choices in the Middle East as binary: either attempt to maintain the existing regime of undemocratic, family-governed "states" (Saudi Arabia, Jordan, Morocco, the Persian Gulf emirates) and of dictatorships (Egypt), or transform that regime into one of democratic nation-states modeled on our own.

American policymakers and analysts must think beyond these two choices. Historians of international relations, constitutional scholars and students of international law are familiar with other structures of governance besides the nation-state. Before the 1648 Peace of Westphalia recognized the modern nation-state, and indeed well after it, the international system witnessed a broader diversity of forms of sovereignty, including city-states, empires and loose regional confederations-and overlapping religious or ethnic authorities, such as the Catholic Church. In more recent times, the period between the end of the First World War and the rapid decolonization that followed the Second World War might provide models other than the nation-state structure for governing failed states. Moreover, even if it is considered necessary or desirable to maintain the nation-state structure, it is altogether different to insist on preserving pre-existing national borders.

As to the possibility of alternate models of governance: State failure or dysfunction may indicate that a territory or a population is not best governed by a nation-state structure at all. Both the League of Nations (in the "mandate" system) and the United Nations (in the "trusteeship" system) once recognized certain forms of quasi-sovereignty. These systems were considered transitional: a developed nation would take charge of a territory and guide it toward full sovereignty and independence. Maintaining these forms of mixed sovereignty need not be a short-term project, however. If a territory and population cannot govern themselves, the United States could best protect its security interests by staying for quite a long time.

Unlike a traditional "empire", the United States would not be maintaining control to extract economic benefits from a territory-in fact, recent experience has shown that the flow of funds would be in the other direction. But the expenditure of American resources would have the greater long-term payoff of preventing a territory from becoming a failed state and thus becoming a haven for terrorists or the scene of massive human rights abuses. In its recent interventions in Somalia, the Balkans and Afghanistan, the United States and its partners have not considered the option of such an alternate form of governance, but instead have sought to impose nation-state structures within pre-existing borders, often those arbitrarily chosen by empires long ago.

To be sure, a mandate or trusteeship system might be burdensome both from the viewpoint of the local population and from that of the administering power. From the first angle, such a regime might seem far too close to colonialism; from the second, it would impose heavy policing and other costs that yield no immediate pay-offs. The unexpectedly swift collapse of Western colonialism after the Second World War, which has left so many failed states in its wake, was due to the interaction of these very factors: the demands of native elites for self-governance on one side, the heavy burdens and bad consciences that go with empire on the other side. Both problems might, perhaps, be neutralized if the administration were entrusted to the United Nations or to a consortium of burden-sharing outside states rather than to a single one. But experience with the UN's administration of Kosovo indicates that such an arrangement could also be resented as colonialist, and the difficulties NATO has encountered with burden-sharing in Afghanistan (attested by the wide disparity in casualty rates between the U.S.'s forces and those of some of its European partners) suggest that such arrangements are inherently liable to break down.

The second possibility-that national boundaries might be considered revisable-may therefore make more sense. We are already living through a period of fragmentation-in 1945, for example, there were 74 independent nations; today, there are 195 (counting Taiwan and Palestine). National boundaries were extensively rewritten in the wake of the collapse of Soviet communism, as new states (Ukraine, Kazakhstan) and old (Estonia, Armenia) emerged from the wreckage of the Soviet Union and as former communist states in central Europe (Czechoslovakia, Yugoslavia) divided along linguistic, ethnic or sectarian fault lines. Why not divide Rwanda, for example, into two countries, or Iraq into three?

Consider the Iraqi case more closely. Perhaps as a result of the Gulf War, which was fought to preserve the territorial integrity of Kuwait, the United States and its coalition do not seem to have seriously considered partitioning Iraq so as to bring the political institutions of that territory into closer alignment with the distribution of its main ethnic (Arab and Kurdish) and sectarian (Shi‘a and Sunni) groups. Indeed, the status of the United States and the United Kingdom as "occupying powers" under Security Council Resolution 1483 (2003) and its successors signals a determination that Iraqi sovereignty and borders are to remain intact. Yet even in the recent past, the United States has not treated national boundaries as immutable. In 1999 and after, the United States and its allies have in effect been party to severing Kosovo from its nominal sovereign, Serbia; indeed, with the creation of a "no-fly" zone in northern, Kurdish-dominated Iraq in 1992 and its maintenance for over a decade after, the United States encouraged an already-powerful demand for Kurdistan's secession and independence. Given that the boundaries of Iraq have never corresponded to any underlying realities of language, ethnicity or faith, and given also that sectarian and ethnic conflicts threaten to tear the flimsy fabric of Iraqi nationhood apart, why should Iraq's boundaries be considered unalterable?

Of course, partitioning Iraq into three new countries could invite outside intervention from Iran, Turkey or elsewhere. If the United States gave no guarantees for the security of the three successor states, they would probably either band together or be conquered. Even after most of our forces withdrew, the United States would have to supply the three new nations with the security against foreign threats that was originally provided by the larger Iraq. But protecting the successor states from their external enemies would require a much smaller force than what is needed for counterinsurgency, and one more suited to the kind of wars our military is best at fighting.

Downsizing states may be desirable (or inevitable) anyway. Some economists have argued that the size of nations is determined by the trade-off between benefits of larger scale-such as defense, law and order, and free trade markets-and the costs created by heterogeneity of preferences within a nation. While larger nations can provide public goods at lower per capita costs, at some point they will become so large that heterogeneous groups within the nation would rather split apart than live under policies which they oppose. This has, indeed, been one of the main reasons historically why large, internally diversified nations and empires (like the Austro-Hungarian Empire or the Soviet Union) have collapsed: The costs to Estonians of remaining inside the Soviet empire, or to Czechs of remaining inside the Austrian one, came to outweigh any benefits they derived from the efficiencies of greater national scale.

For more than half a century, the United States has supported an international system that has supplied most of the globe with external security and free trade-the very public goods that larger nation-states had existed to provide. It follows that, as the threat of interstate war recedes and free trade agreements expand, nation-states should tend to become at once smaller and more homogeneous: The benefits of size will be provided by the international system, not by the (large) nation-state. By playing the "hegemonic" role of principal supplier of international public goods, the United States has created the exact conditions to encourage national fragmentation-a development it now paradoxically opposes by attempting to keep nations intact. One could view the blood and treasure spent in Iraq as the costs of opposing broader trends in history toward smaller, more homogeneous nations and governments, trends in fact accelerated if not put in motion by American foreign policy itself.

Partitioning, to be sure, is not necessarily a panacea for political violence. The two great twentieth-century partitions undertaken by a disintegrating British Empire-those of Ireland and of India-have not produced peace in either land. Even where partitioning ostensibly "worked", as in Germany between 1945 and 1989 or in Korea from the 1953 armistice until the present, it was maintained only because it was a solution imposed by the great powers. Further, partition and other forms of boundary revision could provoke mass deportation or ethnic cleansing, as the partition of India in 1948 did, with calamitous results, and as the shift westward of Poland's boundaries in 1945 also did-on that occasion, however, with benign long-term effects for the peace of central Europe. The partitioning of Iraq is, therefore, a risky, if also defensible, policy option.

But Iraq is only one example of a deeper reorientation that should occur in American foreign policy, away from the democratic nation-state model and toward more flexible forms of governance. The United States should reject the notion that it must bring failed states to democracy, national independence and full sovereignty. Perhaps in partnership with other nations, it should explore other forms of governance that before all else provided internal security, an impartial justice system and functioning markets. Striving first for the grail of constitutional democracy and national sovereignty may be self-defeating. In any case, the more ambitious project raises the costs of intervening to restore order in failed states to what can swiftly become unacceptable levels. Holding down the costs of American intervention is a vital consideration: It will allow us to remove more territory from the grip of dangerous tyrants and terrorists.

The perfect should not become the enemy of the good. The United States should seek to achieve more modest goals of restoring sufficient order in a failed state to prevent it from becoming a breeding ground for terrorism. While the United Nations has generally proven a poor resource for achieving these ends, the United States might benefit from working with nations with large militaries and populations that could specialize in providing order within failed nations. For example, the United States might try to work out arrangements with countries like India, Turkey or Egypt under which they would be paid for providing sufficient military personnel to repress insurgencies and maintain order in a failed state, thus enabling the United States to concentrate on other tasks.

Second, the United States and its allies should consider more seriously the prospect of fragmenting failed states into more governable parts. If the United States and its allies continue to supply international peace and security, and current efforts to promote free trade succeed, existing nations may often be larger than necessary. The United States should reject efforts to keep failed states together, and instead allow them to break up along ethnic or religious lines.

Robert Delahunty is an associate professor of law at the University of St. Thomas School of Law, Minneapolis, MN. John Yoo is a law professor at the University of California, Berkeley, a visiting scholar at the American Enterprise Institute and the author of War by Other Means(Grove/Atlantic, 2006).